Four-Parameter Taylor Series-Based Light-Emitting-Diode Model

This paper presents a light-emitting-diode (LED) model based on the four-parameter Taylor series to describe the V-I characteristic of the LED at different junction temperatures. Therefore, in order to precisely model the LED nonlinear characteristics at different junction temperatures, an improved Taylor series-based LED model is proposed according to the four available parameters: 1) maximum operating point; 2) rated operating point; 3) knee point; and 4) temperature coefficient obtained from the LED V-I curves. Furthermore, in order to perform the dc and small-signal simulation and analyses of the LED drivers at different junction temperatures, the proposed model can be used to derive the LED dc and small-signal equivalent resistances at different junction temperatures. Finally, the measured results are compared with the modeled V-I curves, dc equivalent resistances, and small-signal equivalent resistances of the experimental LED at different junction temperatures.